// Problem: 
// Contest: 
// URL: 
// Memory Limit: 
// Time Limit: 
// #pragma GCC optimize("Ofast")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
#include<bits/stdc++.h>
using namespace std;
#define int long long
inline int read(){
	int s=0,w=1;
	char ch=getchar();
	while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
	while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
	return s*w;
}
signed main()
{
	int n;
	cin>>n;
	cout<<n<<endl;
	vector<int> v(n+1);
	//int x;
	for(int i=1;i<=n;i++)cin>>v[i];
	int t;
	cin>>t;
	vector<int> e(t+1);
	int hash[64]={0};
	for(int i=1;i<=t;i++)cin>>e[i];
	for(int i=1;i<=n;i++)
		for(int j=1;j<=t;j++)
		{
			if(v[i]==e[j])cout<<v[i]<<" ";
		}
	cout<<endl;
	for(int i=1;i<=n;i++)
		hash[v[i]]++;
	for(int i=1;i<=t;i++)
		hash[e[i]]++;
	for(int i=0;i<=63;i++)
	{
		if(hash[i]>0)cout<<i<<" ";
	}
	cout<<endl;
	return 0;
}
